As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Computers, including servers and workstations, are often grouped into computer networks, including networks having a client-server architecture in which the servers access storage, including shared storage, in response to requests from client computers of the network. The servers of a computer network may include one or more virtual operating systems running on the host operating system and the host software of the server. Each virtual operating system comprises a virtual machine. Multiple virtual machines may be included on a single physical server. The presence of one or more virtual machines on a single physical machine provides a separation of the hardware and the software of the computer system. Each virtual machine could be dedicated to the task of handling a single function. As an example, one virtual machine could be a mail server, while another virtual machine present on the same physical server could be a file server.
A server cluster is a group of independent servers that is managed as a single system and is characterized by higher availability, manageability, and scalability, as compared with groupings of unmanaged servers. A server cluster typically involves the configuration of a group of independent servers such that the servers appear in the network as a single machine or unit. Server clusters are managed as a single system, share a common namespace on the network, and are designed specifically to tolerate component failures and to support the addition or subtraction of components in the cluster in a transparent manner. At a minimum, a server cluster includes two or more servers, which are sometimes referred to as nodes, that are connected to one another by a network or other communication links.
Failure recovery of business applications running on enterprise servers has been addressed through solutions such as hot standby solutions, backup/restore operations, and failover clustering. Failover clustering provides an automated mechanism for restarting applications by failing them over to a passive server and restarting the application. Failover clusters deploy passive server machines to take over failures from active servers. These passive servers, which are either physical or virtual machines, continue to consume physical and logical resources while they wait for failures to happen.
The use of the same reference symbols in different drawings indicates similar or identical items.